Drill



y o. B. ANDERSON 2,242,739

DRILL Filed Aug. 15, 1939 2 Sheets-Sheet 1 D G M L v I? M j N VEN TOE0/. OF B. ANDE/E 501v ATToRNE-YJ May 20, 19141; R ON 2,242,739

DRILL I Filed Aug. 15, 1939 2 Sheets-Sheet 2 A p I 3 2614223 272 270 3 8Q? m4 new Y/Z ATTOKNEW Patented May 2%, 1941 DREL Olof B. Anderson,Minneapolis, Minn, assignor ts E. J. Longyear Company, Minneapolis,Minn, a

corporation of Delaware Application August 15, 1939, Serial No. 290,311

(or. 2ss 4s) 8 Claims.

The present invention relates to an improved earth drill which isparticularly adapted for the high speed drilling of exploration and.blasting holes through rock and the like.

In the drilling of rock, the most commonly used. bit consists of amatrix or form in which there are set a plurality of cutting diamondswhich serve as cutting and abrading edges to wear away the rock as thedrill is rotated. In order to drill satisfactorily with diamond drills,it is necessary to provide a continuous stream of Water at the drill bitand to this end it has been customary to use a hollow drill rod anddrill spindle through which water is forced to the bit while it is beingrotated.

The water supply to the hollow drill spindle is normally made through arotatable connection which is attached to the upper end of the drillrod.

In the drilling of deep holes, particularly in close quarters as wherethe drilling is being done within the close confines of a mine, it isnecessary to use a drill rod composed of many sections, each of thesections being from 20 to 60 inches long, depending upon the workingspace avail able.

According to previous drilling practice, it has been customary to use adrilling machine having a hollow spindle through which the drill rodsare advanced, each new section of drill rod being attached to thepreceding sections above the machine and advanced through the machine asthe drilling proceeds until finally the desired hole depth is obtained.

As explained above, the water connection is at the upper end of thehollow drill rod and hence in order to add each new section to the drillrod, it has been necessary to disconnect the water swivel from the drillrod, then add the additional section and finally again reconnect thewater swivel for further drilling operations.

Time studies have indicated that frequently as much as 80% of the totaloperating time of the machine is consumed in the non-productiveoperations of adding the drill rod sections, connecting anddisconnecting the water swivel, unchucking and rechuclring, running thedrill spindle back, and the like, only 20% of the total time being usedin actual drilling operations.

It is an object of the present invention to provide an improved drillingapparatus in which the time which must be consumed in non-productiveoperations is greatly reduced.

It is a further object of the invention to provide an improved drillingapparatus which is capable of much higher speeds than those heretoforeobtainable, and capable of rapid connection and disconnection of thedrill rod for the insertion and removal of drill rod sections.

It is also'an object of the invention to provide a drilling apparatus inwhich the drill rod sections may be connected and disconnected by powermeans obviating the use of hand tools for tightening and loosening thejoints in the drill rod sections. I

It is a further object of the invention to provide an improved drillingmachine in which, if desired, the raising and lowering of the drill rodspindle may be accomplished with great rapidity, or when desired slightmovements completely under direct control of the operator may beaccomplished during connecting and disconnecting operations of the drillrod.

It is a further object of the invention to provide an improved drillingapparatus in which the drill rod in the hole may quickly and firmly beheld against movement during the connecting and disconnecting operationsand then quickly released for the ensuing drilling operation.

It is a further object of theinvention to provide an improved drill rodgripping apparatus capable of use with the drill at any angle and inwhich regardless of the angle of drilling, the aforementioned rapidconnection and disconnection of the drill rods may be accomplished.

Other objects 'of'the invention are those inherent'in and implied by themethod and apparatus herein illustrated, described and claimed.

The invention is illustrated with referenceflto the drawings in whichFigure 1 is a side elevational viewpartly in section of the drillingapparatus.

Figure 2 is an end elevational view in the direction of arrows 2-2 ofFigure 1.

Figure 3 is a sectional view along the line 33 of Figure 2.

Figure 4 is a side elevational view partly in section of the drillingapparatus, the upper section portions being taken along the line 4-4 ofFigure 2, and the lower sectional portions being taken along the line 55of Figures 2 and 3.

Throughout the drawings, like numerals designate corresponding parts.

The illustrated embodiment of thepresent invention'includes a motordevice M, which rotates in one direction, a gear box device G, whichtransmits the power of the motor in either direction of rotationand adrill D, which is the driven unit. In Figure 1, these parts are shownbeneath the brackets designated M, G and I) re spectively. The motor Mand gearbox G may be separate, or unitary devices the desideratum beingrotary motion of the requisite horsepower available in either directionof rotation. The horsepower required varies widely from a few horsepowerfor shallow small diameter drilling to upwards of 20 horsepower and insome instances even more, for large diameter deep hole drilling. It isusually more convenient to use a unidirectional air motor or internalcombustion engine, and a forward and reverse gear, but where electricityor steam is available reversible motive power units are more convenient.

In the illustrated embodiment of the invention the motor mechanism M isa positive displacement pneumatic motor I which is supplied by an airfeed line II, having a throttle valve I2 therein.

The motor includes a face plate I3 and a power shaft I4 to which thereis attached a spur gear I5. Gear I5 meshes with spur gear IS on shaft I?of the gear box unit G.

The motor I5 which has an air relief valve 22, is attached to the gearbox housing 20 by a plurality of bolts 2| and the housing 20 is in turnattached to the main gear housing 30 by means of bolts, not illustrated.At the base of the gear housing, there is a frame member 3! of anyapproved type, by which the entire apparatus is supported, the frame 3Ibeing shaped so that it may readily be attached to a conventional tableor jack such as are used for supporting drilling device.

At-Jthe motor end of the gear box housing 30, there is provided abearing retainer 32, carrying a pair of ball bearings 33. The ballbearings 33 serve rotatably to support the shaft H, which receives'powerfrom the motor by way of gears i6. and I5. The inwardly protruding endof shaft I'I isformed with a gear 40, which meshes with a large idlergear 4| on shaft 42. A second smaller idler gear 43 is formed integrallywith gear M and rotates therewith and meshes with a reversing gear 44.

Within the gear portion 43 of shaft Il, there isa pilot bearing 58,preferably of the needle roller'type, which serves to support the end 55of shaft 55, the other end of shaft 55 being rotatably mounted in a ballbearing race 56, carried on the gearing box housing 30 by means ofthejbearing retainer fiii. The bearing 56 is held inth'e retainer 58' bymeans of a member 59, which also contains a grease packingring 60.

The shaft 55 is splined at 62 and upon it, there is mounted a slidinggear 51 which is illustrated in its neutral position in Figure 1. Gear51 has internal teeth. 62, which mesh with the end of gear 4%! when thegearis moved to the right in the view Figure 1, and external teeth 63which mesh with reverse gear 44 when the gear 51 is moved to the left inthe view Figure 1. The gear 51' is provided with a groove 65 in whichthere is a forked shift lever 65, the latter being mounted for movementto the right and to the left (Figure 1) by means of a slide rod 61. Theentire arrangement of slide rod' 61 and forked rod 66 mounted thereonis'arranged to be shifted by means of shift lever it. Thus the gearshifting apparatus has three positions, namely: forward, reverse andneutral, and the mechanism may be held in either of. these positions bythe detent mechanism generally designated II.

The ratio of gaming housed in the gear box G. is such that the forwardand reverse drives are approximately" the same speed for a given motorspeed.

The gear box housing 39 isprovided with a smoothlyfaced-circular flange80 at the left asshown inFigure 1, upon which there is mounted acircular ro-tation'plate 8I, having an internal. .TI-shaped circulargroove 82. Suitable T-shaped bolts, not illustrated, have their headsin-groove 3 2 and protruding through the faced fla 35 of the gear boxserve to attach the rotation plate 80 to the gear box. The rotationplate may be turned with reference to the gear box for shifting thedrilling head as will be explained hereinafter.

At the outer end of shaft 55 of the gear box, there is provided abeveled gear I00, which serves to transmit power to a similar beveledgear IOI of the drill head generally designated D. The drill headconsists of a shaped housing generally designated I20, which is providedwith a conically surfaced edge I2I, which serves to position the drillhead co-axially with respect to the shaft 55 of the gear box when thedrill head is in operative position on the rotation plate 8|. Thehousing generally designated I20 is provided with a hinge I whichcooperates with cooperating hinge parts I26 on rotation plate 8I. Thehinge pin I21 couples the parts I25 and I25 together for hinging actionabout the pin.

At the opposite side, the drill head is provided with a pair ofprotruding lugs I30 and I3I, between which there is positioned anangularly shaped fastening bolt I33. The bolt I33 is bent at rightangles and is preferably mounted upon the lugs I34 of rotation' plate8|. The outer end of bolt I33 is provided with a nut I36 and as a resultthe drill head may be drawn into close engagement with the rotationplate by tightening the nut I36 on bolt I33. The conical surface I2I ofthe drill head housing which nests in the similar conical surface I 22of the rotation plate thus serves accurately to position the drill headwith reference to the rotation plate when the two are drawn together asjust described.

In the lower part of the drill head housing, there is provided a bearingplate I40 which serves to mount the ball bearing I M, the latter beingheld in place by a retainer ring I42 by means of bolts I43. The retainerI43 also serves to carry a grease seal I44. Within the housing I20,there is another ball bearing l50, which is mounted upon the internalhousing portion I5I, and the bearings MI and I serve rotatably to mountthe hollow drill shaft generally designated I60. The drill shaft isprovided near its-lower end with a flange IBI against which there ispressed a spur gear I62. Above the spur gear, there is pressed the bevelgear IOI, which, as previously described, meshes with the gear I00 onthe gear box shaft. Below the flange IGI there is mounted the inner raceof bearing I4I, the race being held in place by a spacing collar andbottom nut I63.

At the upper end of the drill head housing I20, there is provided arecess I which contains a bearing retainer Ill. The bearing retainercarries a pair of ball bearing races I12, which are held downwardly inplace by the bearing retainers I13, which in turn are held by means ofan upper cap I14 bolted to the housing I20 by a plurality of bolts I15.

The bearings I72 serve rotatably to support an internally threaded feednut generally designated I which is provided with a lower shoulder I SIagainst which the inner races of bearings I12 are tightly seated. Abovethe bearings, there is provided a spacing collar I8I and above these apair of drive gears I82 and I83. Above the drive gears, there isprovided a hand wheel I84; all of these are held in place upon the feednut by a nut and lock nut I85.

Within the hollow drill shaft generally designated I50 and theco-axially aligned feed nut generally designated I80, there is athreaded hollow drill spindle generally designated 200, which isthreaded throughout its length (as shown at 20!) so as to cooperate withthe internally threaded feed nut I80. The hollow drill spindle is alsoprovided with one or more longitudinal key ways 202, which cooperatewith internal keys on the hollow drill shaft I60. As a result, thehollow drill shaft I69 serves to rotate the spindle whereas the spindleis advanced or retracted by relative rotation with respect to the feednut I80.

At the left side of the drill head housing as shown at Figure 2, and asshown in the broken away part of the housing Figure 4, there is provideda feed nut drive arrangement having a shaft generally designated 22%.The shaft 220 is rotatably mounted in its lower end in an antifrictionbearing, preferably a needle roller bearing 22!, and at the lower end ofthe shaft there is mounted a gear 222 for rotation with the shaft. Thegear 222 meshes with gear I62 as shown in the dotted lines in Figure 2and serves to rotate the shaft 220 as the hollow drill shaft rotates.

The upper end of the feed nut shaft 220 is likewise mounted in ananti-friction roller bearing 224 which is held in place by a spacingcollar 225. Above the spacing collar, there are mounted gears 226 and221 which are of slightly different diameter, and rotatably mounted withreference to the shaft 220, being held in place upon the shaft by meansof a nut and lock nut 228.

The upper half of the shaft 220 is hollow as shown at 230, the hollowportion extending down-' wardly to 23!. Near the lower portion 23!, theshaft 220 is provided with oppositely disposed side slots 232, one ofwhich is shown, and at the upper end there is provided a pair ofsimilarly disposed and shown slots 233.

Within the opening 230 of shaft 220, there is mounted a shift rod 240,which is provided with a cross pin 24! near its lower end and withanother cross pin 242 at its upper end. The pin 2M serves to attach theshift rod 240 to an external circular rack 243, which is slidablymounted upon shaft 220, the rack 243 being provided with circular teeth244 which mesh with a shift gear, not illustrated, on shift rod 245.This shift rod 245 is mounted in an external pillow block 245, which isattached to the drill head housing by means of a plurality of bolts 241.At the outer end of the shift rod 245 there is provided a shift handle268 by which the rod may be rotated with the result that the circularrack 243 is moved upwardly or downwardly on the shaft 220. This shiftingof the circular rack 243 and the attached internal shift rod 240 may beaccomplished while the apparatus is in rotation or while it isstationary.

The spring detent generally designated 245a is provided between theinner surface of circular rack 243 and the shaft 220. It has a neutralposition in which 242 is out of mesh with gears 225 and 221, an upperposition in which pin 2 52 is in mesh with inner notches on ear 221, anda lower position in which pin 242 is in mesh with gear 225.

The gears 226 and 221 are continuously in mesh w h ears I82 and H33,respectively. on the feed at H89. The gear ratio of the gear pa r 22$ 2.is slightly different than the gear ratio of the gear pair 221|83, andwith either pair of gears the feed nut 6 is driven at a slightly lesserrate than the spindle.

While only two pairs of feed gearsare illustrated, it is obvious thatwhere rock hardness conditions vary widely, require a greater ratio thanis possible with two gears, additional gears and shifting box may easilybe added.

The threading upon the drill spindle 200 is right-hand and the feed nutI is driven at two speeds, depending upon whether gear 226 or 221 is thedriving gear. Each of the feed nut drive speeds is less than the spindlespeed and as a result, the spindle is accordingly advanced downwardly asit is rotated in the right hand direction. Thus when the spindle isrotated thru 1000 turns, the feed nut may be rotated 994 or 940 turns,which represents one and ten inch feed where the pitch of the spindlethread is six per inch.

At the lower end of spindle 220, there is provided a hexagonal wrenchportion 250, which is formed integrally with the drill spindle 200. Be-

neath the wrench portion 250, there is provideda certain drill rodcoupling which has a. standard drill rod coupling thread of six threadsper inch. In the present apparatus, the threads 20! on the drill spindleare made of the same pitch as the threads 25! for a purpose which willbe described below.

Extending downwardly from the rotation plate 8| there are a pair of legs260, which converge downwardly and are joined together by web 26! at adistance from 30 to 40 inches below the drill rod. At the lowerconnected ends of the legs 260, there is provided a mechanism forselectively engaging and holding the portion of the drill rod whichremains in the hole, all for a purpose to be described.

The mechanism for engaging and holding the drill rod is preferablyformed integrally with the downwardly extending legs 26!], although insome instances it may be desirable to use separate elements which areattached to the leg portions.

In the illustrated embodiment of this mechanism the two legs 260 arejoined together at their lower ends by a unitary casting havingcylindrical end portions 262 and 263. Between the cylindrical endportions there is a displaced section having an upper surface 264 and. alower surface 265, (Figure 2), which extends from the plane 266 to theplane 251 as shown in Figure 2.

Each cylindrical end portion 262 and 263 is bored to form cylinders 2113and 21!, the cylindrical bores being continued to the lines 212 and 213respectively. The bore 215 of smaller diameter is continued from theplane 212 directly thru to the plane 213 and thus intersects the outersurfaces of the casting represented by planes 264 and 265 thus leavingan opening 3 through the casting, which is bounded by the lines 28l282and 265251. Within the cylinders 210 and 21!, there are placed plates232 and 283, which have square central openings as shown at 235 inFigure 4, each of the plates being attached to its cylinder by means ofa bolt 286 each plate is thus preventedfrom rotation'within'thecylinder. V

Within cylinder 21!], there is provided a piston 288 which is preferablymade from a cut leather washer. The piston 288 is supported on thereverse side by a metal washer 289 behind which there is a spring 29!],which is provided for the purpose of retracting the piston in thedirection of the arrow 29L The piston rod 292 is square and thus slidesneatly through the square opening 285 of plate 282. The piston is thusprevented from rotating with reference to the cylinder although it isfree to move longitudinally. 7

At the outer end of the piston rod 292, there is provided a cylindricalhead 294, which is of the same diameter as bore 215, and at the free endof the head, there is provided a transverse semi-circular notch 295,having teeth 296. Both the notch 295 and teeth 2% are aligned with thedrill spindle. The diameter of the semicircular portion 295 is the sameas that of the drill rod being used.

Cylinder 2' is provided with a similar piston rod and outer cylindricalhead for gripping the drill rod, all as described with reference tocylinder 210.

On the side of the cylinders toward legs 25!), there is provided atransverse bore 238, which intersects with a. bore 297 of cylinder 2'")and a bore 299 of cylinder 2H. Tothe bore 291, there is attached an airfeed line 305 having a control valve 3M by which air to the cylindersmay be turned on and off. The valve 30I is preferably provided with ableed part to exhaust the air or other motive fluid from the cylinderswhen the air supply to them is interrupted. The bore 299 is stoppered bymeans of screw plug 302 and the bore 298 is likewise stoppered by meansof plug 303. The outer ends of the cylinders 210 and 21! are providedwith cylinder heads 355 and 336 respectively, which are attached to thecylinders by means of a plurality of cylinder bolts 38?. A gasket 388 ispreferably provided between the cylinder head and the cylinder body.

At the upper end of the drill spindle 2Il'0,there is provided a swivelwater connection generally designated 320, to which there is attached awater hose 3ZI. This swivel connection may be of any acceptable varietycapable of delivering water to the spindle while the spindle is rotatedat high speeds.

In Figures 2 and 4, the portion of the drill rod which extends into thehole being bored is illustrated at 330, the surface of the rock or earthbeing shown at 332.

Operation In the operation described below, it will be assumed that thedrill is mounted over a surface being bored and that the drill spindlecoupling portion 259 is closely adjacent the drill head housing I20,that the drill rod is coupled to the drill spindle at threads 25I, andthat the drill is not rotating, but is ready for the drilling operation.It is assumed further that water is being supplied tothe swivel joint320-and therethrough to the diamond bit, not illustrated, at the lowerend of the drill rod.

1. In order to initiate the operation, the operator shifts the gear boxhandle 1B into the forward drive position in which gear 51 is located tothe right as shown in Figure 1 into engagement withgear 40. The handle248 is then moved to one or the other of its extreme positions whichshifts the pin 242 into engag ment with one or the other of the feed'drive gears 226 or 221 thereby providing a feed drive through gears I 82and I83 to the feed nut I 80.

The valve 33! of the drill rod assembly is moved to the off position andsprings 290 within cylinders 27!! and 2' move their respective pistonsto the retracted position with the result that the cylindrical drill rodengaging and holding heads 294 are moved out of en age ment with thedrill rod.

The throttle valve I2 of engine II! is then opened and the drill beginsto rotate and is fed downwardly, the drilling being continued until thespindle has approached the limit of its downward travel. at which timethe hexagonal end 250 of the spindle will be closely adjacent thecylinders 210 and 2'.

2. The air supply to motor I0 is then discontinued, and air valve 35I ismoved to the on position with the result that pistons 288 are moved totheir operated position. This forces the heads 294'into engagement withthe portion 330 of the drill rod in the hole and prevents any rotationor longitudinal movement of the part of the drill rod within the hole.The shaft handle I0 is then moved to the reverse position, the feedshaft 245 is mo'ved to the neutral position by means of handle 248 andthe motor II) started by opening valve I2. At the same time, theoperator firmly grips hand wheel I84 so as to prevent the feed nut I83from rotating. The spindle 2GB is accordingly rotated towards themachine, and since the threads 251 of the coupling to the drill and thethreads 2! of the feed screw are of the same pitch, the spindle 200 isscrewed upwardly and out of connection with the drill rod 330 withoutlongitudinally disturbing the drill rod. This is important inasmuch asit is undesirable on the one hand to force the diamond bit intoengagement with the end of the hole and likewise undesirable to retractthe drill rod and attached diamond bit from engagement into the bottomof the hole. When the threaded coupling 25I is disconnected, the drillrod is rapidly withdrawn due to the fact that at the time the operatoris holding the feed nut I89 stationary. With the feed nut stationary theupward movement of the spindle is very rapid as compared with the downfeed of the spindle during drilling operations since the differential ofspeed between spindle and feed nut is at this time equal to the spindlespeed. By way of comparison it maybe noted that when the feed nut isrotated during drilling there is only a slight differential of speedbetween the spindle and feed nut.

3. As soon as the spindle 20B is fully retracted, a fresh section ofdrill rod is screwed on to the drill rod 330, which is .at the time heldtightly in place due to the action of cylinders 21B and 2' which are inthe operated condition. The fresh section of drill rod may have a shortspace between its upper end and the then retracted screw coupling 25I,and in order to bring down the spindle into engagement with the upperend of the fresh section of drill rod, the operator may merely turn thehand wheel I84 if the distance is small and thus bring the threads ofthe spindle into alignment with the threads of the newly added sectionof drill rod. Preferably, however, the operator shifts handle 70 intothe forward drive position and the throttle I2 of motor I0 is slightlyopened so as slowly to rotate the motor with the result that the spindleis brought downwardly into engagement with the newly added drill rodsection. During this running down, as in the retracting operation previously described, the operator holds wheel I84 of the feed nut. In thismode of operation the threads 25I may run directly into the threads ofthe newly added section of drill rod since by holding the feed nut Istationary the downward movement of the spindle 203 through each turn isequal to the pitch of threads 25I in the then stationary drill rod. Dueto this correspondence in pitch, there is no tendency to displace thedrill rod 330 in the hole either to lift the same from the end of thehole nor is there a tendency to force the drill rod against the bottomof the hole with excessive pressure.

At this juncture it may be explained that excessive pressure on thedrill rod may ruin the diamond bit and may even lift th drillingapparatus due to the pressure on the bit. When the latter occurs thealignment of the drilling apparatus with the hole is changed, all withundesirable consequences. Likewise, lifting the bit oi the bottom of thehole is undesirable since it must then be run down into contact with thehole before drilling can be resumed.

4, After the threaded coupling 253 has been screwed into the freshsection of drill rod as previously described, the shift handle 248 ofthe feed screw drive is moved into one or the other of its operatedpositions and with the gear box lever Hi already in the forward driveposition and valve Bill and cylinders 210 and 2' moved to the offposition drilling may be resumed by opening the throttle valve 12 ofmotor l5.

Drilling is then continued as described under paragraph 1 above.

The aforementioned operation may be carried out with equal facilityregardless of whether the drill is being operated in a vertical positionor at some angle other than vertical since in any position the drill rodengaging and holding arrangeent is accurately positioned and alignedwith respect to the spindle and drill rod by means of legs 28%].

Many obvious variations may be made in the apparatus herein describedwithout departing from the spirit of the invention. Thus, in someinstances, it is desirable to use a hydraulic feed mechanism in place ofthe mechanical feed screw mechanism here described, and in someinstances it is desirable to use a reversible electric, or pneumaticmotor in place of the engine M and reverse gear box G here described.Likewise, the illustrated mounting of the drill head D may be widelyvaried to meet the exigencies of particular installations and the methodof mounting the drill rod engaging and holding arrangements (cylinders210 and 21!) may be changed to suit any particular design. Thuscylinders 210 and 2'Il need not be pneumatic but may be a hydraulicmechanism operated, for example by a foot pressure on a master cylinder,or a mechanical device for accomplishing the desired result of holdingthe drill rod while the fresh section of drill rod is being added, maybe used.

These and many other obvious variations will be apparent to thosefamiliar with the art and may be made without departing from the broadscope of the invention claimed.

What I claim is:

1. A drilling device comprising drill spindle means having a feed screwmeans thereon, motor means for driving the spindle means in eitherdirection, feed nut means, hand means connected with the feed nut forrotating the feed nut by hand and disconnectable drive means forrotating the feed nut means from the spindle means during drilling.

2. A drilling machine comprising a spindle, means including screwthreads on said spindle and cooperating feed nut means for advancingsaid spindle through a predetermined distance, a drill rod axiallyaligned with said spindle, and means including a screw threadedconnection having threads of the same pitch as those on the spindle forconnecting the drill rod and spindle.

3. A drilling machine comprising a spindle,

means including screw threads on said spindle and cooperating feed nutmeans for advancing said spindle through a predetermined distance, adrill rod axially aligned with said spindle, means including a screwthreaded connection having threads of the same pitch as those on thespindle for connecting the drill rod and spindle and means on saidmachine for engaging and holding the drill rod.

4. A drilling machine comprising a spindle, means for rotating thespindle in either direction, means including threads on said spindle anda cooperating nut means for axially moving the spindle through apredetermined distance in either direction as it is rotated, a drill rodarranged in line with said spindle and a screw threaded joint forconnecting the drill rod and spindle end to end, the threads of saidjoint being of the same pitch as the threads on said spindle,disconnectable means for rotating the feed nut means as the spindlerotates to axially move the spindle, and hand means for controlling therotation of the feed nut means when said disconnectable means forrotating is disconnected.

5. A drilling machine comprising a spindle,

, means for mounting said spindle for movement through a complete circleof radial positions, said movement being about an axis at right anglesto the axis of said spindle and through said spindle, means for rotatingsaid spindle about its own axis, means for moving said spindle axiallythrough a predetermined distance as it rotates about its own axis, aclamp means mounted on said means for mounting said spindle, said clampmeans being positioned axially with respect to said spindle beyond thelimit of axial movement of the spindle.

6. A drilling machine comprising a frame, a spindle mounted for rotationand for axial movement with respect to said frame, means for rotatingthe spindle, means for axially moving the spindle including threads onsaid spindle and a cooperating feed nut, means for rotatably mountingsaid feed nut, mechanical drive means for rotating the feed nut at aslightly different speed than the speed of said spindle, means forinterrupting said mechanical drive means, and hand wheel means connectedto said feed nut for rotating the same.

'7. A drilling apparatus comprising a spindle, a drill head mounting thespindle for rotation and for advancing and retracting axial movementthrough a limited path, power means for rotating and axially moving thespindle, means mounting the drill head for free turning movement about adrill head axis which is through the spindle and at right anglesthereto, said drill head having a frame extension thereon and aplurality of clutch jaws mounted on the frame for movement toward andfrom the drill spindle axis, said jaws being positioned beyond the limitof advancing movement of the spindle, whereby the jaws may grip a drillrod attached to the spindle, in any radial working position of the drillhead.

8. A drilling device comprising drill spindle means having a feed screwmeans thereon, motor means for driving the spindle, feed nut means, handwheel means connected with the said nut for rotating the feed nut byhand, and disconnectable drive means for rotating the feed nut meansfrom the spindle means during driving.

OLOF B. ANDERSON.

